Which expression is equivalent to x5 • x9?

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Acircle has a circumference of 7.850 units. what is its radius?

Which of the following equations is equivalent to x/3-6/x=1